Date: Thu, 21 Aug 1997 09:49:59 -0700 (PDT)
From: Dean Gaudet <dgaudet@arctic.org>
To: new-httpd@apache.org
Subject: Re: Tristate responses from module hooks
In-Reply-To: <97082111034374@decus.org>
Message-ID: <Pine.LNX.3.95dg3.970821094917.21439H-100000@twinlark.arctic.org>
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A pain, but not impossible, to implement because it requires extra state
to be kept for the array of function pointers.

Dean

On Thu, 21 Aug 1997, Rodent of Unusual Size wrote:

>     I proposed this once before, but I don't think it resulted in any
>     discussion.  If that happens this time too, I'll take the hint. <g>
> 
>     How about adding another response possible from module request-phase
>     hooks: OK, DECLINED, and NEXT_PASS (or whatever)?
> 
>     The idea is to allow modules (such as mod_rewrite) to say, "I've
>     done what I want to do, but I feel compelled to take a look at what
>     any other you call after me modules do to make sure they don't
>     scroodle me."
> 
>     The module-hook caller would make a note of the response from each
>     module:
> 
>     1. If none return NEXT_PASS, we're finished.
>     2. If any return NEXT_PASS, watch for subsequent ones returning OK
>        or NEXT_PASS.  If none do, we're finished.
>     3. Start over at the first NEXT_PASS hook, and re-call any that
>        returned NEXT_PASS or OK the last time.  If the results are the
>        same as last time, return a server error (probably a deadlock).
>     4. Repeat [3] until everything returns either OK or DECLINED.
> 
>     There are probably flaws with this sequence.  Modules that want to
>     use the call-me-if-anything-changes mechanism would need to maintain
>     some sort of state, probably in the r->notes table.
> 
>     Just a wild idea, probably started by thinkos from that high-energy
>     particle bombardment I accidentally wandered through.. <g>
> 
>     #ken    :-)}
>